Disassembling And Reassembling The Radio - General - Motorola GP200 Series Service Manual

3-4
To replace a chip component using a soldering iron, select the appropriate micro-tipped
soldering iron and apply fresh solder to one of the solder pads. Using a pair of tweezers,
position the new chip component in place while heating the fresh solder. Once solder wicks
onto the new component, remove the heat from the solder. Heat the remaining pad with the
soldering iron and apply solder until it wicks to the component. If necessary, touch up the first
side. All solder joints should be smooth and shiny.
To replace a chip component using hot air, select the hot-air hand piece and reflow the
solder on the solder pads to smooth it. Apply a drop of solder paste flux to each pad. using a
pair of tweezers, position the new component in place. Position the hot-air hand piece
approximately 1/8" above the component and begin applying heat. Once the solder wicks to
the component, remove the heat and inspect the repair. All joints should be smooth and shiny.
Shields
Removing and replacing shields will be done with the R-1070 station with the temperature control
set to approximately 415°F (215°C); 445°F (230°C) max.
To remove the shield, place the circuit board in the R-1070's holder. Select the proper heat
focus head and attach it to the heater chimney. Add solder paste flux around the base of the
shield. Position the shield under the heat-focus head. Lower the vacuum tip and attach it to
the shield by turning on the vacuum pump. Lower the focus head until it is approximately 1/8"
(0.3cm) above the shield. Turn on the heater and wait until the shield lifts off the circuit board.
Once the shield is off, turn off the heat, grab the part with a pair of tweezers, and turn off the
vacuum pump. Remove the circuit board from the R-1070's circuit board holder.
To replace the shield, add solder to the shield if necessary, using a micro-tipped soldering
iron. Next, rub the soldering iron tip along the edge of the shield to smooth out any excess
solder. Use solder wick and a soldering iron to remove excess solder from the solder pads on
the circuit board. Place the circuit board back in the R1070's circuit board holder. Place the
shield on the circuit board using a pair of tweezers. Position the heat-focus head over the
shield and lower it to approximately 1/8" above the shield. Turn on the heater and wait for the
solder to reflow.
Once complete, turn off the heat, raise the heat-focus head and wait approximately one
minute for the part to cool. Remove the circuit board and inspect the repair. No cleaning
should be necessary.
5.0 Disassembling and Reassembling the Radio — General
Since these radios may be disassembled and reassembled with the use of only four (board to
casting) screws, it is important to pay particular attention to the snaps and tabs, and how parts align
with each other.
The following tools are required for disassembling the radio:
Small flat blade screwdriver
penknife-size screwdriver
TORX™ T6 screwdriver
Chassis opener (6680702Z01)
If a unit requires more complete testing or service than is customarily performed at the basic level,
send this unit to a Motorola Authorized Service Centre. (See Chapter 1 for a list of authorized
service centres.)
MAINTENANCE